So I put up my fence - green meshing, 50 and 60 cm tall, 5 m of each. That wouldn't deter the jackdaws and fieldfares, though - they'd just fly in. (Pheasants don't fly, as a rule. Remind me to tell you of the flying pheasant ...)

So I had read, a year or two ago, that they'd tried to keep gulls off one or the other dump by stringing string, thick enough to be visible to those birds - the idea being, birds live on their wings, they don't want to hurt them, they avoid strings. (It didn't work, but that was because it's very very difficult to string string across an enormous acreage.)

So I put in strings.

It works, except that fieldfare chicks hide in the tall grass behind the stump, get into the cage from underneath, and can't get back out again. Which means that their parents defy the strings and hop in to feed them. The chicks are easy to catch and easy to eject, but I'd hate to see them trapped in there for longer than a few hours.